• 대한조선학회논문집
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• 제43권3호
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• pp.294-303
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• 2006

A surface piercing propeller (SPP) in tunnel has been proposed recently as a new propulsion system for a high speed air cavity ship. The purpose of the present study is to investigate the characteristics of the SPP in tunnel through a series of model tests. A model propulsion system is placed on a dummy body made of Acrylics. The tunnel is divided into two regions by a guide vane extending from the inlet to the center of the propeller shaft. Air has been supplied from an air nozzle placed at the bottom of the dummy body and the changes in propeller performances caused by the air flow are investigated. The measurements are done for open water and in-tunnel conditions, both for fully and partially submerged propeller. The influence of the guide vane configurations on the propeller performance is also studied. The experiments are performed at the variable pressure circulation water channel of Inha University

• 한국항공우주학회지
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• 제32권8호
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• pp.129-137
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• 2004

본 연구에서 시험부 크기 $30mm{\times}35.6mm$, Run Time 20초인 소형-저가의 초음속 풍동을 개발하였다. 개발원 교육용 초음속 풍동은 단속적 불어내기식형이며 , 노즐 블록 교체형으로 설계되었다. 본 연구를 통하여 초음속 풍동에 사용되는 대형-고가의 기계장비를 기존 소형의 상용 제품으로 대체하여 제작 단가를 낮추었다. 그리고 초음속 풍동의 핵심 기술인 노즐 설계를 비롯한 전체적인 초음속 풍동 설계 기술을 확보하였다. 풍동 시험부에서의 초음속 유동장 형성 및 유동 안정성에 대한 성능검증 실험을 수행하였다.

• 신재생에너지
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• 제2권2호
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• pp.28-36
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• 2006

Numerical analysis of wind turbine scale effect was performed by using commercial CFD code, Fluent. For the numerical analysis of wind turbine, the three dimensional Navier-Stokes solver with various turbulence models was tested. As a turbulence mode, the realizable k-e turbulence model was selected for the simulation of wind turbines. To validate the present method, performance of NREL (National Renewable Energy Laboratory) Phase VI wind turbine model was analyzed and compared with its wind tunnel test and blind test data. Using the present method, numerical simulations for various size of wind tunnel models were carried out and characteristics were analyzed in detail. For wind tunnel test model, the size of nacelle may not be scaled down precisely because of available motor. The effect of nacelle size was also computed and analyzed though CFD simulation. The present results showed the good correlations in pre-stall region but much to be improved in post-stall region. In 2006 and 2007, the performance and the scale effect of standard wind turbine model will be tested in KARI(Korea Aerospace Research Institute) LSWT(Low Speed Wind Tunnel) and the present results will be validated with the wind tunnel data.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.431-434
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• 2009

Conceptual study of an open-circuit type low-speed wind tunnel for test of wind turbine blade is conducted. The tunnel is constituted of a settling chamber, a contraction, closed and open test sections, a diffuser, two corners, a cross leg and a fan and motor. For the performance test, the closed test section width of 1.8 m, height of 1.8 m and length of 5.25 m is selected. The open test section with dimension width of 1.8 m, height of 1.8 m and length of 4.14 m is adopted for aeroacoustic test. The contraction ratio is 9 to 1 and maximum speed in the closed test section is 67 m/sec. Input power in the tunnel is about 238 kW and its energy ratio is 3.6. The wind tunnel designed in present study will be an effective tool in research and development of wind turbine.

• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.107-117
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• 2007

A surface piercing propeller (SPP) in tunnel has been proposed recently as a new propulsion system for a high speed air cavity ship. The purpose of the present study is to investigate the characteristics of the SPP in tunnel through a series of model tests. A model propulsion system is placed on a dummy body made of Acrylics. The tunnel is divided into two regions by a guide vane extending from the inlet to the center of the propeller shaft. Air has been supplied from an air nozzle placed at the bottom of the dummy body and the changes in propeller performances caused by the air flow are investigated. The measurements are done for open water and in-tunnel conditions, both for fully and partially submerged propeller. The influence of the guide vane configurations on the propeller performance is also studied. The experiments are performed at the variable pressure circulation water channel of Inha University.

• 한국항공우주학회지
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• 제36권4호
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• pp.321-327
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• 2008

극초음속으로 비행하는 추진기관이 직면하는 고속 유동 등 제반 현상을 모사하기 위한 지상시험 설비로 충격파 풍동을 설계, 구축한 후 성능 시험을 수행하였다. 개발된 준 일차원 작동 해석를 이용하여 설계점을 파악한 후, 극초음속 시험설비 구축을 위한 개념 설계를 완료하였다. 이어 단위 해석 코드를 이용하여 구체적인 성능 설계 및 각 구성품에 대한 설계를 완료, 구축한 후, 다양한 운용조건에서 성능시험을 수행하였다. 본 논문에서는 이론해석 결과를 바탕으로 이루어진 개념 설계와 준 1차원 다화학종 해석 코드를 이용한 개념설계 검증 및 성능설계 결과 등 극초음속 충격파 풍동 설계방법을 제시하였다.

• 대한기계학회논문집B
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• 제20권11호
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• pp.3695-3705
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• 1996

We designed the hot wind tunnel to reproduce the conditions of utility boiler and carried out its performance test, in order to investigate the particulate two-phase flow behaviour, the fouling and heat transfer characteristics to the heat exchanger. The hot wind tunnel introduces the control system to control the temperature in the test section. The particle is injected into the hot gas stream. The fouling probe (cylindrical tube) is positioned normal to the particulate gas-particle two-phase flow and cooled by the air. The temperature of gas and cooling air, and temperature in the fouling probe are measured as a function of time, giving the local and averaged heat transfer and fouling factor. The shape of particulate deposition adhered to the fouling probe is also observed.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.107-112
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• 2006

A wind tunnel simulation requires high-performance computing power like supercomputers and deep knowledge of this subject. Those requirements make win tunnel simulation difficult. Grid technology will make these difficulties simpler by providing easy to use grid web portal. By using grid web portal, scientist can execute simulation and access to high-performance computing power without any serious difficulties. In this paper will present a grid web portal for a wind tunnel simulation that is used in Aerospace area.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권2호
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• pp.57-67
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• 2010

Experimental investigations were carried out on an Axi-symmetric Body Model fitted with Pump-jet Propulsor (PJP) in the Cavitation Tunnel at Naval Science and Technological Laboratory (NSTL). The tests were intended for evaluating the propulsion characteristics of the body and propulsor. The self propulsion point of the model for two configurations was determined after finding the corrections for tunnel blockage effects and differences in model length at zero trim. The results were found to match closely with the towing tank results. The rotor and stator torques also matched closely over full range of experiment. Further experiments were carried out on the body at $4.5^{\circ}$ angle of trim to investigate the propulsive performance and assess the operational difficulties in the sea. The results indicated an increase in resistance and decrease in rotor thrust; but the balance of torques between the rotor and stator was undisturbed, causing no concern to vehicle roll.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(II)
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• pp.1059-1064
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• 2002

The behavior of an opening and the performance of support system depend upon the load-deformation characteristics of ground and support as well as of the manner and of timing of support installation. The load-deformation characteristics of ground and support are derived by the interaction between ground and support. The interaction between ground and support is qualitatively illustrated by a ground response curve. The behavior of an opening and the performance of support system depend upon the load-deformation characteristics of ground and support as well as of the manner and of timing of support installation. The interaction between ground and support is qualitatively illustrated by a ground response curve. The convergence-confinement method don't need the basic assumptions for a mathematical model. Also This is applicable to general tunnel. Consequently the stability of tunnel must be qualitatively investigated by a ground response curve and quantitatively adjudged by a numerical analysis for the reasonable design of tunnel.